Children's T-shirts are commonly made from knit fabric, which is knitted in the shape of a relatively large diameter continuous tube. The fabric tube may include a pattern, such as continuous stripes of contrasting color running circumferentially around the tube. Such a fabric tube may be flattened and rolled up for storage upon a large spool. In the clothing factory, a spool of such fabric tube is unwound onto a cutting table and folded in zig-zag fashion to form a stack of fabric plies wherein the same flattened fabric surface faces upward and downward in alternate layers of the stack. The layers of fabric in the stack are then cut simultaneously using a pattern so that adjacent layers or plies of the stack will form the front and back pieces of a garment, such as a T-shirt. By retaining the adjacent plies together during the manufacturing process, it becomes possible to match the striping on the front and back pieces. Accordingly, each pair of adjacent layers of the cut fabric is used to form the front and back of a single garment.
Current manufacturing techniques utilize hand labor: (1) to separate adjacent front and back plies from the stack, (2) in some cases, to further cut the front ply near the neck opening, as is required in V-neck T-shirts for example, and (3) to then stitch the front and back plies along the shoulder seam with the outside surfaces of the front and back plies facing each other. The orientation of the inner and outer surfaces of the fabric plies during the sewing of the shoulder seam is the opposite of the orientation of those surfaces in the stack of cut fabric.
In this age of rising labor costs, such labor-intensive manufacturing techniques make the resultant garments increasingly expensive. Also, quality control is more difficult when the uniformity of output is dependent upon unwavering human attention to such highly repetitive handlabor tasks.
Automation of the above-identified hand labor operations would help garment manufacturers in countries where labor costs are relatively high to remain competitive in the face of lower hand labor costs elsewhere. It should also help improve productivity and quality control.
Accordingly, it is the principal object of the present invention to provide a machine and method for automatically removing adjacent front and back pieces from a stack of fabric plies, properly orienting and positioning these pieces adjacent one another, and joining these pieces together by sewing a shoulder seam.
It is also noted that handling, orienting, positioning and sewing are operations which typically each occur a number of times in the manufacture of most articles of clothing or other items made of fabric. Equipment and techniques used to automate any one of these operations, or any combination of these operations, may thus find application in various manufacturing situations in a clothing factory or the like.
Accordingly, it is an object of the present invention to provide an apparatus and method for automatically removing a top ply of fabric from a stack of fabric plies from a position and orienting it so that one surface of the fabric which was facing up is now in a position wherein the same surface faces down.
It is another object of the present invention to provide an apparatus and method for automatically aligning or mating two pieces of fabric adjacent one another so that the pieces may later be sewn together along at least one seam.
One other object of the present invention is to provide for a novel chain having pins projecting therefrom that is useful for automatically transporting fabric from one place to another.
Yet another object is to provide an apparatus and method for automatically transporting fabric or similar material in a selected path along a surface, such as through a sewing machine, while maintaining said fabric or material in proper alignment by use of the aforementioned pin chain.
Still another object of the present invention is to provide a machine which automatically performs all of the aforementioned objects without operator intervention beyond the loading of fabric stacks and unloading of stacked sewn garment portions, thereby making it feasible for a single operator to attend to a plurality of such machines.